1 /* 2 * devfreq_cooling: Thermal cooling device implementation for devices using 3 * devfreq 4 * 5 * Copyright (C) 2014-2015 ARM Limited 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 12 * kind, whether express or implied; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #ifndef __DEVFREQ_COOLING_H__ 18 #define __DEVFREQ_COOLING_H__ 19 20 #include <linux/devfreq.h> 21 #include <linux/thermal.h> 22 23 24 /** 25 * struct devfreq_cooling_power - Devfreq cooling power ops 26 * @get_static_power: Take voltage, in mV, and return the static power 27 * in mW. If NULL, the static power is assumed 28 * to be 0. 29 * @get_dynamic_power: Take voltage, in mV, and frequency, in HZ, and 30 * return the dynamic power draw in mW. If NULL, 31 * a simple power model is used. 32 * @dyn_power_coeff: Coefficient for the simple dynamic power model in 33 * mW/(MHz mV mV). 34 * If get_dynamic_power() is NULL, then the 35 * dynamic power is calculated as 36 * @dyn_power_coeff * frequency * voltage^2 37 * @get_real_power: When this is set, the framework uses it to ask the 38 * device driver for the actual power. 39 * Some devices have more sophisticated methods 40 * (like power counters) to approximate the actual power 41 * that they use. 42 * This function provides more accurate data to the 43 * thermal governor. When the driver does not provide 44 * such function, framework just uses pre-calculated 45 * table and scale the power by 'utilization' 46 * (based on 'busy_time' and 'total_time' taken from 47 * devfreq 'last_status'). 48 * The value returned by this function must be lower 49 * or equal than the maximum power value 50 * for the current state 51 * (which can be found in power_table[state]). 52 * When this interface is used, the power_table holds 53 * max total (static + dynamic) power value for each OPP. 54 */ 55 struct devfreq_cooling_power { 56 unsigned long (*get_static_power)(struct devfreq *devfreq, 57 unsigned long voltage); 58 unsigned long (*get_dynamic_power)(struct devfreq *devfreq, 59 unsigned long freq, 60 unsigned long voltage); 61 int (*get_real_power)(struct devfreq *df, u32 *power, 62 unsigned long freq, unsigned long voltage); 63 unsigned long dyn_power_coeff; 64 }; 65 66 #ifdef CONFIG_DEVFREQ_THERMAL 67 68 struct thermal_cooling_device * 69 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, 70 struct devfreq_cooling_power *dfc_power); 71 struct thermal_cooling_device * 72 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df); 73 struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df); 74 void devfreq_cooling_unregister(struct thermal_cooling_device *dfc); 75 76 #else /* !CONFIG_DEVFREQ_THERMAL */ 77 78 static inline struct thermal_cooling_device * 79 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, 80 struct devfreq_cooling_power *dfc_power) 81 { 82 return ERR_PTR(-EINVAL); 83 } 84 85 static inline struct thermal_cooling_device * 86 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df) 87 { 88 return ERR_PTR(-EINVAL); 89 } 90 91 static inline struct thermal_cooling_device * 92 devfreq_cooling_register(struct devfreq *df) 93 { 94 return ERR_PTR(-EINVAL); 95 } 96 97 static inline void 98 devfreq_cooling_unregister(struct thermal_cooling_device *dfc) 99 { 100 } 101 102 #endif /* CONFIG_DEVFREQ_THERMAL */ 103 #endif /* __DEVFREQ_COOLING_H__ */ 104